During a local ant build of Clojure (tested with master after release of 1.6.0-beta1), the script/run_test.clj is executed. As a side-effect on the Mac, the Java coffee cup app icon is placed in the Dock, and the test app becomes the active application on the desktop. This is slightly annoying.

Even with this property set, activation of awt causes focus to switch temporarily then switch back (at least on Mac).

Patch CLJ-1353-v2.patch is identical to Steve Miner's CLJ-1353-no-mac-dock.patch, except it adds another line to build.xml to set the property there, too. At least on my Mac systems, an icon appears in the dock during compilation, not only during testing, and this added line prevents that. Keeps Steve as the patch author.

I tested CLJ-1353-v2.patch on a Linux system, too, and at least the messages that appear on the console during the execution of "ant" are identical with and without this patch, so no extra warnings appear due to these extra properties being set that are likely ignored by the JVM there.

I found that even with this property, I still see focus change, then come back, during the build due to the activation of awt. Adding the java.awt.headless=true property made that stop. I updated the patch in both locations and now on Mac focus is never stolen during the build.

FYI: If you see the Java "Allow incoming network connections?" dialog on Mac during the tests in response to creating the Sockets in test/clojure/test_clojure/java/io.clj (test-socket-iofactory), this procedure makes that stop:

In my testing, the addition of the java.awt.headless=true properties in both build.xml and src/script/run_tests.clj was sufficient to avoid the additional icon appearing, and also avoiding any change of focus. Setting apple.awt.UIElement=true appears to be unnecessary (but harmless).

Yes, it seems that java.awt.headless=true is a better, more general solution for the build process. I think apple.awt.UIElement would be appropriate if you actually needed AWT for user interaction but didn't want the dock icon.